Rotary snowplow

ABSTRACT

A TWO-STAGE ROTARY SNOWPLOW, THE FRAME STRUCTURE INCLUDING A HOLLOW CROSS BEAM ON WHICH IS MOUNTED THE IMPELLER AND IMPELLER HOUSING. THE BEAM IS DIVIDED INTO COMPARTMENTS AND SERVES TO COOL THE FLUID FOR THE HYDRAULIC OPERATING MOTORS. THE MAXIMUM FLUID PRESSURE   SUPPLIED TO THE AUGER MOTOR IS LESS THAN THE MAXIMUM FLUID PRESSURE SUPPLIED TO THE IMPELLER MOTOR WHEREBY, UNDER A CLOGGED CONDITION, THE INFEED AUGERS WILL STALL, WHILE THE IMPELLER CLEARS THE PLOW OF ACCUMULATED SNOW.

June 8, 1971 v E. A. FARRELL 3,533,034

ROTARY SNOWPLOW Filed Dec. 4. 1968 '7 Sheets-Sheet 1 III FIG I I l v j 8 m G I INVHNTUR. EUGENE A. FARRELL. BY

ATTORNEY June 1971 E; A. FARRELL 3,583,84

ROTARY SNOWPLOW Filed Dec. 4. 1968 7 Sheets-Sheet 2 IN VIiNTUR. EUGENE A, FARRELL. BY

ATTORNEY.

June 8, 1971 E. A. FARRELL 3,583,084

ROTARY SNOWPLOW Filed Dec. 4, 1968 7 Sheets-Sheet 3 IN vlsw'ron. EUGENE A. FARRELL ATTORNEY June 8, 1971 E. A. FARRELL 3,583,084

ROTARY SNOWPLOW Filed Dec. 4, 1968 7 Sheets-Sheet 4.

n lVIz'N'IHR. EUGENE A. FARRELL.

ATTORNEY.

June 8, 1971 E. A. FARRELL 3,583,084

ROTARY SNOWPLOW Filed Dec. 4, 1968 7 Sheets-Sheet 5 I33 INVI'JN'I'UR.

EUGENE A. FARRELL.

June 8, 1971 Filed Dec. 4, 1968 E. A. FARRELL 3,583,084

ROTARY SNOWPLOW 7 Sheets-Sheet 6 FIG. 7

N Io [98 INVHI'IUR.

EUGENE A. FARRELL 4 NY ATTORNEY.

June 8, 1971 E. A. FARRELL 3,533,034

ROTARY SNOWPLOW Filed Dec. 4, 1968 7 Sheets-Sheet 7 FIG. I2

8 INvI-mrm.

EUGENE A FARRELL.

ATTORNEY.

United States Patent O 3,583,084 ROTARY SN OWPLOW Eugene A. Farrell, Evans Mills, N.Y., assignor to Frink Sno-Plows, Inc., Clayton, N.Y. Filed Dec. 4, 1968, Ser. No. 781,193 Int. Cl. E01h /09 U.S. Cl. 37-43E 12 Claims ABSTRACT OF THE DISCLOSURE A two-stage rotary snowplow, the frame structure including a hollow cross beam on which is mounted the impeller and impeller housing. The beam is divided into compartments and serves to cool the fluid for the hydraulic operating motors. The maximum fluid pressure supplied to the auger motor is less than the maximum fluid pressure supplied to the impeller motor whereby, under a clogged condition, the infeed augers will stall, while the impeller clears the plow of accumulated snow.

BACKGROUND OF THE INVENTION Rotary snowplows universally embody an expensive and complicated structural arrangement whereby it is difficult to remove damaged components, such as the impeller and impeller housing.

BRIEF SUMMARY OF THE INVENTION The rotary snowplow of my invention embodies a simplied frame structure economically fabricated from readily available structural components. The frame structure includes a hollow cross beam on which is mounted the entire impeller drive assembly, and the impeller housing.

The infeed augers and impeller are operated by fluid motors supplied by pumps operated by an engine mounted in the plow frame structure. The fluid is supplied to the hydraulic pumps from a supply tank, through the hollow cross beam which, in addition to supporting the operating components of the plow, also serves as a cooler for the hydraulic fluid before entering the hydraulic pump. The discharge stack from the impeller housing is constructed to receive a loading stack, the direction caps on both stacks being operated by hydraulic motors attached to the discharge stack.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a front elevational view of a snowplow embodying my invention.

FIG. 2 is a side elevational view, with parts broken away, looking to the left in FIG. 1.

FIG. 3 is a rear elevational view.

FIG. 4 is a top plan view with parts broken away, and parts omitted.

FIG. 5 is a rear isometric view of the frame structure.

FIG. 6 is a view taken on line 66, FIG. 1.

FIG. 7 is an enlarged sectional view of the impeller drive assembly also shown at the center of FIG. 6.

FIG. 8 is a rear elevational view of the impeller housing and cylinder for rotating the same, parts being broken away in the view.

FIG. 9 is a view taken on line 9--9, FIG. 8.

FIG. 10 is a rear elevational view of the upper end of the impeller housing discharge stack and casting chute.

FIG. 11 is a view, similar to FIG. 10, illustrating the loading chute.

FIG. 12 is a schematic diagram of the fluid circuit for powering the various motors.

3,583,084 Patented June 8, 1971 DETAILED DESCRIPTION The frame structure of the machine is best shown in FIGS. 4 and 5. The frame consists of vertically disposed side plates 20, 21. A front plate 22 extends between the side plates 20, 21, and is fixed thereto, as by welding. The front plate 22 is spaced rearwardly from the front edges of the side plates. The forward portions of the side plates, extending forwardly from the front plate 22, are of rectangular form. The portion 23 of the side plate 20 extending rearwardly from the front plate 22, is of trapezoidal form. The portion 25 of the side plate 21 extends a substantial distance rearwardly from the rear end of portion 23 of plate 20. A hollow beam 27 extends between the plate portions 23, 25. One end of the beam is welded to the rear end of the portion 23, and the opposite end of the beam is welded to the portion 25 intermediate its length. In its lower area, the front plate 22 is bent to form a forwardly and downwardly inclined flange 31 to which is welded a formed up gusset member 32, the ends of which are also welded to the side plates 20, 21. A scraper blade 33 is detachably fixed to the forward edge of the inclined flange 31, see FIG. 6, as by bolts.

The front plate is formed with a large central opening in which is fixed an annular flange 35 extending a short distance rearwardly of the plate 22. At its upper edge, plate 22 is bent to form a forwardly extending flange 37 merging with an upwardly and forwardly inclined flange 38 terminating in a bent-over portion 40, FIG. 6. Gusset members 41, FIG. 5, are welded to the flanges 37, 38. Wing plates 43 are fixed to the upper edges of the side plates 20, 21, and to the adjacent gusset members 41.

The hollow cross beam 27 is formed with a central aperture in which is welded a cylindrical sleeve 47, FIGS. 5 and 7. An annular plate 48 is welded to the front side of the beam 27 and is arranged in register with the sleeve 47. An inner bearing race 50 is detachably secured to the plate 48, as by cap screws 51.

An impeller housing is positioned intermediate the beam 27 and the front wall 22 of the frame. This housing includes a discoidal rear wall 53, see FIGS. 6, 7 and 8. The rear wall 53 is provided with a circular series of apertures 54 to receive cap screws 55 which serve to attach an outer bearing race 57 to the wall 53. The Wall 53 extends inwardly from the bearing race 57, and this inwardly extending portion is formed with a series of apertures 59, FIG. 8, to receive cap screws 60, which thread into a flange 61 formed on a cylindrical bearing housing 62 extending through the sleeve 47. An impeller arbor 63 is journalled in bearings 64 mounted in the housing 62. The arbor has a forwardly extending portion provided with a circular flange 65, to which the discoidal impeller disk 67 is attached by cap screws 68. The arbor 63 is formed with a portion 69 extending rearwardly and operatively coupled to a hydraulic motor 70 affixed to the rear end of the bearing housing 62, as by screws 71, see FIG. 7. With this arrangement, the impeller housing and the bearing housing 62 are rotatable about the axis of the arbor 63.

The impeller housing includes an annular front wall 73 having a rotating fit on flange 35 carried by the front wall 22. A semi-circular side wall section 75 extends between the walls 53, 73, and is fixedly secured thereto, as by welding. The peripheral wall of the impeller housing is completed by a second semi-circular section 77, the ends of which are provided with angle members 78 abutting against angle members 79 fixed to the section 75. Bolts 80 extend through the angle members 79, 77, this arrangement serving to attach the removable section 77 to the fixed section 75. The removable section 77 is also retained in position by a plurality of tie bolts 83. The rear wall 53 is formed adjacent its periphery with apertures t0 receive the tie bolts 83, and the corresponding portion of the front wall 73 is formed with slots 85. The bolts 83 are formed with flat heads With squared shanks adjacent the heads for insertion in the slot 85. The opposite ends of the bolts extend through the apertures formed in the rear wall plate 53, and are provided with nuts 87.

With this arrangement, it will be apparent that the section 77 may be detached and removed from the housing, whereupon the impeller may be removed by removing the cap screws 68 attaching the back wall of the impeller to the arbor. This permits convenient removal of the impeller for repair or replacement without disturbing any other parts or structures of the plow. Theimpeller includes a series of radially disposed blades 90, to which paddles91 are attached, as by screws 93, see FIG. 6. This impeller structure is conventional in rotary plows of this type.

The front and rear walls 73, .53, and the fixed wall section' are shaped to form a discharge opening to which a discharge stack 95 is attached and extends tangentially with the impeller for the discharge of snow. The rear wall 53 of the impeller housing is provided with a bracket 97 to which the outer end of a piston rod 98 is attached. The piston rod extends from a fluid-operated cylinder 100 pivotally mounted at its lower end to a bracket 101 attached to the portion 23 of the side wall 20. The piston and cylinder structure serves to effect rotation of the impeller housing on the bearing structure 50, 57.

A pair of angers are mounted intermediate the forward portions of the side plates 20, 21. These are of conventional arrangement including shafts 105 journalled at their ends to bearings 106 mounted on the inner surfaces of the plates 20, 21, and each shaft is provided with right and left hand helices 107. The turns of the helix, at the centers of the shafts, are formed with radially extending projections 110 which serve to break up compacted snow and ice, see FIG. 1. The augers feed the snow laterally to the opening in the front wall for entrance into the impeller housing.

The forward portion of the front wall 21 is inclined outwardly, as at 111, FIG. 4. A vertically disposed plate 112 is welded to the forward edge of the inclined portion, see FIG. 2. An upper plate 113 is formed with an inwardly bent flange 114, which is welded to the top edge of the plate 21. There is a similarly arranged lower plate 115. The auger shafts 105 extend outwardly through the side wall 21, and are provided with sprockets 117. A chain 118 is trained over the sprockets 117 and over a sprocket 4 rotatably attached thereto by a bearing assembly 141.

' Brackets 143 are fixed to the stack and serve to support a 120 mounted on the output shaft 121 of a fluid operated motor 122 fixed to the inner surface of the side plate 21. A take-up idler sprocket 123 is provided, see FIG. 2.

A cover 125 is formed with a rectangular forward portion, and a trapezoidal rear portion. The forward edge of this cover is inserted between tabs 127, 128, fixed on the inner and outer surfaces of the plate 112 along the rear edge thereof. The cover is retained in place by a screw 129, FIG. 2, threading into the side wall. Other than the forward edge of the cover, the edges thereof are bent inwardly to abut against the side plate 21 to provide a removable closure for the chain drive for the augers.

It will be understood that the apparatus is suspended from the front end of a powered vehicle, such as a motor truck. Adjustable skids 133 are attached to the side plates for supporting the plow on the surface from which the snow is being removed. Legs 134 are provided at the rear end of the frame structure which serve to support the plow in horizontal position when it is removed from the motor vehicle.

As previously stated, the impeller housing is rotated about the axis of the impeller arbor 63 by the piston and cylinder structure 100, FIG. 8. This is the conventional arrangement for casting the snow from a rotary plow either to the right, or to the left. The housing stack 95 is provided at its upper end with a circular flange 137. A snow casting chute'140, forming an extension of the stack 95, is

fluid operated motor 145. The output shaft of the motor is operatively connected to the casting section by a chain drive 147. The motor is of the reversible type and serves to rotate the casting section chute about the axis of the stack 95 in either direction.

A casting cap 148 is pivotally mounted to the upper end section 140 on pins 150. A cylinder 151 is connected to the section 140. The piston rod 152 is connected to a cross head 153 slidably mounted in U-shaped guards 154 fixed to the section 140. A pin 155 extends through the cross head, the ends of the pin passing through elongated apertures 157 formed in the casting cap 148. The cylinder and piston structure serves to adjust the cap 148 about its pivotal mounting 150 to cast the snow in the desired direction.

The cap 148 may be removed by extracting the pins 150, 155. A loading chute 160 is adapted for attachment to the upper end of the section 140, and it is provided with a direction cap 161 pivotally mounted at 162. Links 163 are connected at their lower ends to the replaced pins 150, and at their upper ends they are pivotally connected to 165 to the cap 161. The chute 160 and cap 161 are employed to direct the snow into a dump truck traveling alongside the plow when it is used to clear large areas, such as parking lots and airports.

With the arrangement described, by operation of the cylinder 100, the snow can be discharged at either side of the plow, and with the casting chute 140 and cap 148, the snow is discharged laterally from the side of the highway for a distance up to one hundred feet. The cap 148 can be removed, and the loading chute 160 and cap 161 mounted in place of the casting chute in a few minutes for loading trucks.

Fluid power is furnished to the impeller motor 70 and the auger motor 121, together with cylinders 100, 151, and turret motor 145, by pumps operated by an engine mounted in the rear portion of the frame on a plate 171 extending between angle iron cross members 172, FIG. 5. The radiator of the engine is indicated at 177; FIG. 2. The engine 170 is directly connected to twin pumps 178, 179. The oil supply for the fluid system is contained in a supply tank 180 mounted on the inturned top flange 181 of a plate 182 which is positioned inwardly from the side plate 20 and yielded to the front plate 22, see FIG. 5. The tank 180 is also supported on a member 183 fastened between the beam 27 and an upper'rear angle iron 185. The tank is held in place by a retaining strap 187, see FIGS. 3 and 6.

The tank is provided with a filler pipe 190, and an outlet 191, which is connected at 192 to the beam 27, FIG. 5. The beam is provided with a partition member 193 which extends medial of the top and bottom sides of the beam from the end adjacent the plate section 23 to the sleeve 47. A similar partition member 195 extends from the sleeve 47, but terminates in spaced relation to the opposite end of the beam. The inlet from the tank 180 is positioned above the partition 193, whereby the Oil flows to the left, FIG. 5, about the end of the partition 195 and returns through the lower compartment in the beam.

The fluid pressure is produced for the impeller and anger motors 70, 122, by the twin pumps 178, 179. The suction line 198 of pump 178 is connected to an outlet in the bottom side of the cross beam 27. The output of the pump is connected through line 200, to a four-way, twoposition valve 201, operated by a solenoid 202. The outlet from this valve is connected by line 203 to the impeller motor 70. The return line 205 from the motor extends to the tank 180. The valve 201 is provided with a pressure relief, the discharge of which is connected by line 207 to the tank 180. The valve is also provided with a line 208 extending to the supply tank. When the solenoid 202 is deenergized, and the valve shifted to shut off the flow of fluid to motor 70, the fluid is drained from line 203, through line 208, to the supply tank. Accordingly, the motor is not locked when the fluid pressure is discontinued to it.

The auger motor 122 is controlled by a valve 210, which is a duplicate of the valve 201. The fluid is supplied to this valve byline 211, from pump 179, the suction line 212 of which also extends to the bottom of the beam 27.

When actuated, fluid pressure from valve 210 is conducted by line 213 to the auger motor 122. The return from the motor is by line 214 to the supply tank. The pressure relief from valve 210 is by line 215 to the supply tank, and the bleed back from line 213 is through line 217 to the tank when the solenoid 218 of the valve is deenergized.

Three, four-way, three-position solenoid operated valves 220, 221, 222, are employed to control the flow of fluid to the impeller housing cylinder 100, the cap cylinder 151, and the turret motor 145, respectively. The fluid input for these three valves is through line 225 from a small pump 226, also driven by the engine 170, as by the cam shaft thereof. The input line 225 is connected to the valves 220, 221, 222, through a relief valve 227. The discharge from the relief valve is through line 228 to line 240, to the supply tank 180. The suction line 241 for pump 226 is also connected to the bottom side of the beam 27. The ends of the cylinder 100 are connected by lines 230, 231, to the valve 220. The ends of the cylinder 151 are con nected to valve 221 by lines 233, 234. The fluid circuit from valve 222 to the turret motor 145 is through lines 236, 237. The return from these valves is through line 240, to the supply tank.

As previously explained, the fluid is drawn from the supply tank 180, through inlet 192 in beam 27 This fluid circulates lengthwise of the beam about the end of the partition 195, and returns to the bottom compartment of the beam. Accordingly, the beam 27, in addition to forming an important structural member of the frame, also serves to cool the fluid before it enters the pumps 178, 179. This is particularly advantageous in view of the fact that the plow is often parked for considerable periods of time outdoors when the temperature of the atmosphere is substantially below freezing, with the result that even if the plow is parked for a relatively short period of time, the pumps cool down to atmospheric temperature. However, the oil in the supply tank 180, which is of considerable volume, Will under such circumstances remain at a temperature considerably above the atmospheric temperature. Accordingly, if the suction lines to the pumps were connected directly to the supply tank, as. is conventional, the impact of the heated fluid in the cold pumps would result in uneven expansion of the pump components, causing excessive Wear and damage to the pumps- However, the oil in the cooling beam 27 is lowered to atmospheric temperature at substantially the same rates as the pumps and accordingly, there is no difference in temperature between the pumps and the fluid supplied thereto.

The solenoids 202, 218, of the valves 201, 210, and the solenoids 250, 251, 252, of valves 220, 221 and 222, are operated by switches in a console mounted in the vehicle cab, whereby the operator can conveniently control the operation of all of the fluid motors. An important feature of my invention is the fact that the relief of valve 210, supplying fluid to the auger motor 122, is adjusted to operate at a lower pressure than the relief in valve 201. For example, the relief in valve 201 may be set at 2000 pounds per square inch, and the relief in the valve 210 set at 750 pounds per square inch. Accordingly, if the plow is advanced into a deep bank of hard, compacted snow, the augers will stall when the pressure through the valve 210 supplied to the auger motor 122 is no longer able to effect rotation of the augers. However, the impeller will continue to rotate to remove the accumulation of snow and when that takes place, the back pressure against the augers is relieved, and the augers will automatically start to turn. This arrangement avoids the use of overload clutches, shear pins and the like. Overload clutches require frequent maintenance and if a shear pin is severed, it necessitates the operator leaving the cab of the vehicle and engaging in the arduous task of removing the sheared pin and inserting a replacement pin, this procedure being particularly difficult at night time in a snow storm.

What I claim is:

1. A snowplow comprising a frame structure including spaced apart vertically disposed side plates, a front plate extending between said side plates and being fixedly secured at its ends to said side plates rearwardly of the front edges thereof, said front plate being formed with a central opening, a closed hollow cross beam extending between said side plates rearwardly of said front plate, said cross beam being fixed at its ends to said side plates, a bearing housing mounted in said beam, an arbor journalled in said housing and having end portions extending forwardly and rearwardly thereof, a hydraulic motor mounted on said bearing housing and being operatively connected to said arbor to effect rotation thereof, an impeller attached to the forwardly extending portion of said arbor and being disposed intermediate said cross beam and said front plate in registration with the opening there in, an impeller housing attached to said cross beam and encircling said impeller, said housing being formed with a discharge opening and with an intake opening arranged in registration with the opening in said front plate, a power driven hydraulic pump having its outlet connected to said motor, the inlet port of said pump being connected to the interior of said beam, a fluid supply tank connected to the interior of said beam, said beam serving as a cooling receptacle for cooling the fluid be fore entry into said pump.

2. A snowplow as defined in claim 1 and including a fluid circuit including a control valve extending from the outlet of said pump to said motor, a fluid supply tank, a fluid circuit extending from said tank to the inlet of said pump, said circuit including said hollow beam.

3. A rotary type snowplow comprising a frame structure including spaced apart vertically disposed side plates, a front plate extending between said side plates and being fixedly secured at its end to said side plates rear wardly of the front edges thereof, said front plate being formed with a central intake opening, an auger assembly journalled between said side plates forwardly of said front wall, a cross beam extending between said side plates in rearwardly spaced relation to said front plate, said cross beam being fixed at its ends to said side plates and being formed with a central aperture, an annular inner bearing race fixed to the front surface of said cross beam in registration with the opening therein, an outer bearing race journalled for rotation on said inner race, an impeller housing having a discoidal rear wall fixed to said outer race and extending radially inwardly therefrom, said rear wall being formed with an opening in registration with the opening in said beam, a bearing housing positioned in the opening in said beam and being fixed at its forward end to the inwardly extending portion of said impeller housing rear wall, an arbor journalled in said housing and extending forwardly and rearwardly therefrom, an impeller fixed to the forward end of said arbor and a motor fixed to the rear end of said bearing housing and being operatively coupled to the rear end of said arbor, said impeller housing being formed with a front wall having an opening arranged in registration with the opening of the front wall of said frame, and said housing having a discharge opening, said impeller housing and said bearing housing being rotatable about the axis of said inner and outer bearing race structure.

4. A snowplow as set forth in claim 3, wherein said impeller housing is formed with a curved side wall having a portion fixedly secured to the rear and front walls of said housing, and a portion detachably secured thereto.

5. A snowplow as set forth in claim 3, wherein said motor is a hydraulically operated motor.

6. A snowplow as set forth in claim 3, including a hydraulic motor attached to one of said side plates and being operatively connected to said auger assembly, said motor connected to said impeller arbor being a hydraulic motor, and a fluid pressure system providing fluid to said impeller motor at higher maximum pressure than the fluid applied to said auger motor.

7. A rotory snowplow comprising a frame, an impeller housing mounted on the frame for rotation, an impeller journaled for rotation in said housing, a hydraulic motor operatively connected to said impeller to effect rotation thereof, said motor being fixedly connected to said impeller housing, an auger assembly journaled in said frame forwardly of said impeller housing and operable to direct snow into said housing for discharge therefrom by said impeller, said impeller housing and motor being rotatable about the axis of said impeller for adjustment of the discharge of snow from the impeller housing, a second hydraulic motor operatively connected to said auger assembly for operating the same, and means to cause said auger assembly to stall prior to said impeller and including a pressure fluid supply circuit means extending to each of said hydraulic motors, and pressure control means providing fluid to said impeller motor at a higher pressure than the fluid supplied to said auger assembly.

8. A snowplow as set forth in claim 7, wherein said frame includes a hollow cross beam member, said pressurized fluid supply circuit means includes a fluid supply tank connected to said beam, a hydraulic pump means having an inlet connected to said beam and an outlet connected to each of said hydraulic motors, and a return line extending from each of said motors to said supply tank.

9. A rotary-type snowplow comprising a frame structure including spaced apart vertically disposed side plates, a front plate extending between said side plates and being fixedly secured at its ends to said side plates rearwardly of the front edges thereof, said front plate being formed with a central intake opening, a cross beam extending between said side plates in rearwardly spaced relation to said front plate, said cross beam being fixed at its ends to said side plates, an impeller housing disposed intermediate said front plate and said beam, said impeller housing being formed with a front wall disposed in proximity to said front plate and having an opening arranged in registration with the intake opening in said front plate, said impeller housing being mounted on said cross beam for rotation about an axis extending through said intake opening in said front plate to adjust the angle of discharge from said impeller housing, a bearing housing fixedly secured to said impeller housing and extending rearwardly therefrom, an arbor journaled in said bearing housing and extending forwardly therefrom into said impeller housing, an impeller arranged in said impeller housing and fixedly secured to the forward end of said arbor, and an impeller driving motor fixedly secured to the rear 8 end of said bearing housing and being operatively coupled to the rear end of said arbor, said bearing housing and said impeller driving motor being rotatable about said axis in unison with said impeller housing.

10. A rotary-type snowplow as set forth in claim 9 wherein said impeller housing is detachably mounted on said cross beam.

11. A rotary-type snowplow as set forth in claim 9 wherein said cross beam is of hollow construction and said bearing housing extends fore and aft through said beam.

12. A snowplow comprising a frame structure including spaced apart vertically disposed side plates, a front plate extending between said side plates and being fixedly secured at its ends to said side plates rearwardly of the front edges thereof, said front plate being formed with a central opening, a cross beam extending between said side plates rearwardly of said front plate, said cross beam being fixed at its ends to said side plates, an impeller and an impeller drive assembly including a driving motor having a drive shaft carried by said cross beam, said impeller being detachably secured to said drive assembly and being disposed intermediate said cross beam and said front plate, said drive shaft extending to but not through said impeller, an impeller control housing attached to said cross beam and encircling said impeller, said housing being formed with a discharge opening and with an intake opening arranged in registration with the opening in said front plate, said impeller housing being formed with a discoidal rear wall disposed intermediate said beam and impeller, an annular front wall and a circular side wall, said side wall extending circumferentially of said front and rear walls intermediate the same, means detachably securing an arcuate portion of said side Wall substantially in length to said front end rear walls for removal therefrom to permit removal of the impeller radially from said housing.

References Cited UNITED STATES PATENTS 2,508,829 5/1950 Lamy 37-430X 2,777,218 1/ 1957 Kiecker et al. 37-43B 2,858,625 11/ 1958 Rivinius 37-43 3,222,802 12/1965 Kiernan 37-43 3,299,546 1/ 1967 Ibisch 37-43 3,303,588 2/1967 Krause 37-43 3,334,429 8/1967 Price 37-43 3,371,434 3/ 1968 Wandscheer 37-43 3,375,878 4/1968 Dorn 37-43D 3,478,448 11/1969 Bacon 37-43 FOREIGN PATENTS 627,518 1961 Canada 37-43E EDGAR S. BU-RR, Primary Examiner U.S. Cl. X.R. 3 7-24 

